Locality, Certainty and Simultaneity

Non-locality is based on the assumption that an event which affects a system cannot affect another system which is independent of it. Independent systems being defined as systems which are separated by a distance sufficiently large to prohibit one from influencing the other without violating the speed limit imposed by special relativity. But if gravity is instantaneous, then no systems is truly independent which means that all systems are local and can affect each other instantaneously regardless of distance.